The present invention is concerned with a structure for heat transfer tubes for heat exchangers and the like, and more particularly the present invention relates to a structure for heat transfer tubes for providing venting to the ambient of fluid leaking from a fluid flow enclosure to the other.
Heat exchangers are commonly used for the purpose of transferring heat from a fluid, such as a liquid flowing in an enclosure, to another fluid flowing in an adjacent enclosure without intermixing the fluids. Heat exchangers are in common use in some applications of solar heating devices utilizing a fluid, such as a liquid fluid of high heat absorbing capacity, circulating through a primary fluid flow circuit connected to the solar heat absorber, and where it is desired to transfer the heat from the heated fluid in the primary circuit to another fluid, such as ordinary water or air, circulating in a secondary fluid flow circuit. Heat exchangers are also commonly used in marine and in stationary industrial internal combustion engine installations for absorbing heat from the engine closed cooling system, and in nuclear reactors for cooling the reactor and for utilizing the heat generated by the reactor.
Heat exchangers are often complex devices with many welded or brazed fittings and connections, and they are subject to rapid deterioration, especially when one of the fluids has a corrosive action on the wall of the containing vessels, conduits, and junctions. Conventional heat exchangers are bulky, expensive to fabricate, subject to corrosion and prone to develop leaks.
The invention disclosed in the aforementioned application for Letters Patent remedies the inconveniences of conventional heat exchangers by providing a novel structure for heat transfer tubes for use in heat exchangers, which can be mass-produced in convenient sizes and lengths, and which can be cut from stock to any appropriate lengths for fabricating heat exchanger units of any desired capacity by interconnecting by means of conventional fittings. Heat transfer tubes according to the invention disclosed in said application may be mass-produced at low cost on continuous lines or in batches by means of simple tooling, and consist essentially of an assembly of two conventional tubular elements mounted one within the other and held in spaced apart relationship concentrically to each other by simple wall deformation of the elements, thus requiring no separate holding and connecting members, and no welding, soldering or brazing.